There is a saying in forex and stocks trading that "the trend is your friend" this is truth and I really see this as one of the trading secret not to break and it is good you invest from the beginning of the trend in both directions and sell when the trend is about to come to an end.
So many have incurred losses for not doing so, not selling when everything seems to be coming to a bad end, but still holding on and believing that it'll come up again.
In crypto where unpredictability is the other of the day, the trend is truly your friend, you must take advantage of it, buy when the trend is signaling good, and sell when they are ominous signs that it's about to end.